Some of the stuff we buy from China is so cheap, that I wonder how they manage to cover even the shipping costs for the selling price. Now China`s biggest shipping company COSCO is giving us a clue. They just signed a deal with Solar Sailor of Australia, to fit some of their cargo ships with gigantic rigid sails, each the size of a 747 jet`s wing. We`ve looked before at small scale versions of the same idea, but never anything this huge.

Under ocean going conditions, the sails provide enough thrust to reduce fuel consumption by 20-40 percent, while the solar panels covering them deliver power to the crew quarters and navigation electronics. The ship`s ballast is provided by rechargeable batteries, which can drive the boat electrically if needed, and if you have a really stiff wind, the screws can be reversed to further charge the batteries. The giant sails can also be folded flat onto the deck if there`s a threatening storm.

The 30 metre long sails, festooned in photovoltaic panels are expected to catch enough wind to reduce fuel costs by between 20% and 40%, whilst those PV cells will provide the ships with 5% of their electricity. A computer automatically angles the sails for maximum wind and solar efficiency, and if all goes to plan the sails will have recovered their initial cost within four years.